1. Field of the Invention
This invention relates to a method of molding an elastic seal ring integrally on an inner side of a hood portion of a connector housing, the hood portion being adapted to fit on a mating connector housing so as to cause the seal ring to form a watertight seal between the two connector housings.
2. Related Art
One conventional molding method of the type described is disclosed in Japanese Patent Examined Publication No. 5-23030.
FIG. 4 shows a waterproof connector housing A produced by this conventional method. The housing A includes a housing body 1, and a hood portion 3 of a larger size connected to a front end of the housing body 1 through a stepped portion 2, the hood portion 3 being adapted to receive a mating connector housing therein. An elastic seal ring 4 is formed integrally at an inner end portion of the hood portion 3. The elastic seal ring 4 has retaining piece portions 4a which are intimately engaged and held respectively in through holes 3a formed through a peripheral wall of the hood portion 3, the axis of each through hole 3a being perpendicular to the axis of the housing. The housing body 1 has terminal receiving chambers 1a formed therein.
FIG. 5 shows a mold for the primary molding operation of the housing A, and FIG. 6 shows a mold for secondary molding purposes.
In FIG. 5, the upper mold 5 and the lower mold 6 are clamped together to provide a cavity 9, corresponding to a housing-forming portion, therebetween. First, in the primary molding operation, the upper mold 5 is closed in a direction of the axis of the housing A to be molded, and the connector housing is injection molded according to an ordinary procedure. At this time, slide cores 8 are received respectively in transverse holes 7 so as to form passages (retaining holes) 3a through which an elastic material is poured into a seal ring-forming portion to be formed at the inner side of the hood portion. The passages 3a serve also as retaining holes for retaining the retaining piece portions 4a.
Then, in the secondary molding operation, the upper mold 5 is removed, and instead another upper mold 5', having a cavity 10 corresponding to the elastic seal ring-forming portion, is clamped relative to the lower mold 6 holding the housing 1, and the liquid elastic sealing material is poured into the seal ring-forming portion through the transverse holes 7 and the passages 3a from which the slide cores 7 are retracted.
In the above forming method, even during the formation of the elastic seal ring 4 in the secondary molding operation, the slide cores 7, which slide in directions perpendicular to the direction of clamping of the upper and lower molds 5' and 6, must be used. Therefore the mold is complicated, and the manufacturing cost is high.